对2024Al合金进行了固溶处理,采用光学显微镜、场发射扫描电镜、极化曲线、晶间腐蚀、全浸和盐雾试验,研究了淬火方式(空冷和水淬)对2024Al合金的腐蚀性能和腐蚀模式的影响.由于在固溶处理后的空冷过程中有大量第二相析出相,因此空冷试样的耐蚀性明显差于水淬试样,其腐蚀形式为晶间腐蚀和点蚀,而水淬样品主要是发生点蚀.点蚀由晶内杂质相颗粒与基体Al间的电偶腐蚀引起,晶间腐蚀由晶界析出相与其周围的贫Cu区间,以及基体Al与贫Cu区间的电偶腐蚀引起.
The effect of quenching methods such as air-cooled (AC) and water quenched (WQ) treatment on the corrosion behavior and corrosion mode of 2024 Al alloy was investigated by optical microscope, field emission scanning electron microscope, polarization curve, intergranular corrosion, immersion and salt spray corrosion tests. The experimental results showed that the corrosion resistance of the AC 2024 AI alloy was much worse than that of WQ sample, and the corrosion modes of the AC sample were intergranular corrosion (IGC) and pitting whereas only pitting was found on the WQ alloy. The corrosion mechanism of pitting was contributed to galvanic corrosion between coarse impurity phase particles (A1CuFeMnSi) and matrix Al, and IGC resulted from galvanic corrosion between grain boundary precipitates and Cu-depleted zone, as well as Cu-depleted zone and matrix Al.